A fish tape is an electrician's tool which is used to install wires in a conduit. A fish tape is an elongated member made of tempered spring steel, stainless steel, nylon, fiberglass with a nylon jacket, or multi-stranded steel wire. The fish tape is rigid enough to be pushed through a conduit yet flexible enough to bend around corners or curves in the conduit. After the tape has been “fished” or threaded through a conduit, a wire or cable is attached to the end of the fish tape and the tape is pulled back through the conduit, drawing the wire with it to install the wire in the conduit.
Fish tapes are supplied in lengths ranging from 25 to 200 feet. Due to the length of the fish tape, it is usually coiled for manageability. However, the natural resilience of the material makes the coil unruly. The material at all times wants to escape the confines of the coil. That is, it seeks to return to its natural straight condition and thus wants to “spring out” of its coiled condition. Accordingly, the fish tape must be housed in some manner to maintain it in a coiled condition until it is ready to be used.
Traditionally, a housing of some sort has been used to constrain the coils of the fish tape within a chamber formed in the housing. The chamber's walls confine the coil and prevent its natural release. An opening in the housing is provided to allow the tape's exit from and entry into the housing. In some models, a slot is formed around the periphery of the housing. A handle travels around the housing, widening the slot and directing the entry and exit of the tape through the slot.